The CMS HA option increases the availability of your CMS data by means of the following functions and features:

• ACD link failures

  In the recommended HA configuration, ACD data is transmitted across different C-LAN circuit packs or ethernet ports within the Communication Manager system and across different network subnets, thereby reducing the number of potential single points of failure. If one ACD link fails, data collection continues on the second CMS server. You will use the maintenance backup and restore process to recover the missing data onto the CMS server that was connected to the down ACD link.

• CMS hardware failures

  The CMS HA option provides a duplicate CMS server. If a hardware failure occurs on one CMS server, data collection continues on the second CMS server. You can use the maintenance backup and restore process to recover the missing data onto the server that failed. If the CMS server fails, you may need to restore the CMSADM backup. Since you can do a CMSADM backup with data collection on, you can expect a good CMSADM backup and the system can be recovered more quickly.

• Power failures

  The primary and secondary servers should be separately connected to individual uninterruptible power supplies (UPS) on separate protected power circuits. This configuration ensures that both servers will not be simultaneously disabled due to a localized power failure. However, in the event of an extended power outage, impacted servers should be shut down in order to prevent UPS failure and consequent possible data corruption on the server.

• CMS software failures

  The CMS software application is duplicated. If the CMS application fails or a CMS data collection process fails on one CMS server, data collection continues on the second server. The maintenance backup and restore process is used to recover the missing data onto the CMS server that experienced the software failure event.

• CMS maintenance

  Data is not lost during either a CMSADM backup or a maintenance backup. Also, data is also not lost when restoring a maintenance backup, as long as local system administration data is not being restored.

• CMS full version upgrades

  In a HA configuration, one CMS server continues to collect data while the other CMS server is upgraded to the new CMS version. After the first CMS server is upgraded, data collection is turned on for the upgraded CMS server. The second CMS server is then upgraded while the upgraded CMS server continues with data collection turned on. After the second CMS server is upgraded, data collection is turned on for the second CMS server and the data is restored between the two CMS servers. If you upgrade the Communication Manager system with a new release, the interval of data loss is limited to the amount of time it takes to administer the latest contact center release on the Communication Manager system, and pump-up the ACD link.

  For more information, see CMS base load upgrade.